A friend of mine has been having a real hard time with transmissions in his 98 model. The input shaft on the original NV4500 broke. He had that transmission rebuilt. About 3-4 months later something else inside broke. He then replaced it with an NV5600. The first one the company shipped him had the incorrect input shaft size. The second one they shipped him started making noise after about 100 miles so it was pulled and replaced with another unit. That one made it maybe 10,000 miles, started making horrendous noise and then got stuck in sixth gear. Bottom line, who sells a bullet proof NV5600? Or is there a better transmission to swap in? Yes, the truck has some power mods, but nothing really ridiculous.

Thanks,
Danny

 

It sounds to me that the rebuilds were flawed. A properly rebuilt NV5600 will last a long time.

A company should know better than to ship an NV5600 with the smaller input shaft.

The NV5600 is a great trans-- but it needs proper care and maintenance.

FYI-- I use Redline MTL lube with great results, changing every 30K.

jh

 

145,000 miles on mine and only ever had oil changes.

I won't say I beat on mine but it gets worked good most of the time either towing or more spirited driving.

It sounds to me like something was wrong with the rebuilds.

Jeff

 

The NV5600 w/ the 1 1/4" Input which I presume is in your buddys truck as you stated "The first one they sent had the wrong size input" Which would've probably been the 1 3/8".
Anyways, the 1 1/4" where known for syncro problems, so they redesigned some things and came out w/ the 1 3/8" in 01.

I'll look into it, or you can I'm sure you'll dig up something!

 

I would call blumenthals in oklahoma city, ok. They did the 5 to 6 speed conversion for me and I have had no problems.